This invention relates to benzimidazolone derivatives. These compounds have selective cannabinoid(CB)2 receptor binding activity. The present invention also relates to a pharmaceutical composition, method of treatment and use, comprising the above derivatives for the treatment of disease conditions mediated by CB2 receptor binding activity.
In general, CB2 receptor ligands are found to be useful for the treatment of a variety of diseases, including inflammatory pain, nociceptive pain, neuropathic pain, fibromyalgia, chronic low back pain, visceral pain, rheumatoid arthritis, Crohn's disease, ulcerative colitis, asthma, dermatitis, seasonal allergic rhinitis, gastroesophageral reflux disease (GERD), constipation, diarrhea, functional gastrointestinal disorder, irritable bowel syndrome, cutaneous T cell lymphoma, multiple sclerosis, osteoarthritis, psoriasis, systemic lupus erythematosus, diabetes, glaucoma, osteoporosis, glomerulonephritis, renal ischemia, nephritis, hepatitis, cerebral stroke, vasculitis, myocardial infarction, cerebral ischemia, reversible airway obstruction, adult respiratory disease syndrome, chronic obstructive pulmonary disease (COPD), cryptogenic fibrosing alveolitis and bronchitis (see J Pharmacol Exp Ther. 2004 February; 308(2):446-53; Proc Natl Acad Sci USA. 2003 Sep. 2; 100(18):10529-33; Br J. Pharmacol. 2004 August; 142(8):1247-54). However, no compound having benzimidazolone backbone was known as CB2 ligands.
There is a need to provide new CB2 ligands that are good drug candidates. In particular, preferred compounds should bind potently to the CB2 receptor whilst showing little affinity for other receptors. They should be well absorbed from the gastrointestinal tract, be metabolically stable and possess favorable pharmacokinetic properties. When targeted against receptors in the central nervous system they should cross the blood brain barrier freely and when targeted selectively against receptors in the peripheral nervous system they should not cross the blood brain barrier. They should be non-toxic. Furthermore, the ideal drug candidate will exist in a physical form that is stable, non-hygroscopic and easily formulated.